Pressure vessel

ABSTRACT

The present invention relates to a pressure reservoir having a rigid container with a deformable bladder therein dividing the container into two variable volume chambers, each adapted to receive fluid under pressure. A port is provided in communication with one of said chambers and valve means are associated with said port to close the latter. The valve means is controlled by deformation of the bladder upon expansion thereof when fluid is discharged through said port. The valve means is conformed so that a suction effect will be created due to the flow of fluid through said port, which will cause the valve means accurately to center on a fixed seat associated with the port to close the latter and prevent extrusion of the bladder.

United States Patent Mercler et al.

[ 1 July 11,1972

[$4] PRESSURE VESSEL [72] Inventors: Jacques H. Mercler, Paris; FenlandCoplne, Cergy; Carlo Corbelllni, Paris, all of France 2,801,067 7/1957Mercier X 2,300,722 I l/I942 Adams et al. .92/98 X 3,420,273 l/l969Greer 1 38/30 FOREIGN PATENTS OR APPLICATIONS 9l3.487 5/1946 France I38/30 Primary Examinerl5dward J. Earls Attorney-Arthur B. Colvin [57]ABSTRACT The present invention relates to a pressure reservoir having arigid container with a deformable bladder therein dividing the containerinto two variable volume chambers, each adapted to receive fluid underpressure. A port is provided in communication with one of said chambersand valve means are associated with said port to close the latter. Thevalve means is controlled by defonnation of the bladder upon expansionthereof when fluid is discharged through said port. The valve means isconformed so that a suction effect will be created due to the flow offluid through said port, which will cause the valve means accurately tocenter on a fixed seat associated with the port to close the latter andprevent extrusion of the bladder.

5 Claims, 7 Drawing Figures PATENTEDJHL 1 1 1972 SHEET 10$ 3 INVENTORSJACQUES H.HERQ)ER FERNAND C PINE B CARLO LORBELLIN} ATTORNEY PATENTEnJuL1 1 m2 SHEET 30F 3 INVENTORS zs H NFR'VER w Neva (GENE -QEQELnIA/J E I Ydxlpdg ATTORNEY PRESSURE VESSEL As conducive to an understanding of theinvention, it is noted that in pressure vessels of the above type wherethe valve member is either mounted in the port of the container orcarried by the bladder, it is essential that the valve member when movedagainst its seat to close such port, do so in manner to precludeextrusion of the bladder into such port which would cause cutting of thebladder upon full closure of the valve member with resultant rupturethereof and failure of the pressure reservoir.

It is accordingly among the objects of the invention to provide apressure reservoir of the above type in which a movable valve membercontrolling the oil port will dependably close to cut off discharge offluid, with assurance that the bladder will not be extruded through theport and be cut or ruptured by the closing movement of the valve member.

According to the invention the pressure reservoir has a bladder thereinwhich is initially charged with gas under pressure and subsequentlycompressed or deformed by admission of a fluid such as oil underpressure through an associated port. A valve member is associated withsaid port and designed to be moved by the bladder against a seatencompassing said port upon expansion of the bladder. The valve memberis conformed so that it has a concavity in its undersurface which, as aresult of the rapid flow of fluid from the port, will cause a suction tobe developed, thereby quickly moving the valve member against its seatand centering the valve member for dependable closing action, prior tomovement of the portion of the bladder adjacent the valve member intothe port, thereby preventing extrusion of such bladder.

In the accompanying drawings in which is shown one or more of variouspossible embodiments of the several features of the invention;

FIG. I is a longitudinal sectional view of a pressure vessel accordingto the invention, the valve member being separated from the seat;

FIG. 2 is a fragmentary detail view similar to FIG. 1 in which the valvemember occupies an intermediate position;

FIG. 3 is a view similar to FIG. 2, but corresponding to the position ofcomplete closing;

FIG. 4 is a fragmentary sectional view of another embodiment of theinvention;

FIG. 5 is a fragmentary sectional view of still another embodiment ofthe invention, the closing element being represented in open position;and

FIGS. 6 and 7 are views similar to FIG. 5 but in which the valve memberoccupies respectively a semi-closed and a completely closed position.

Referring to FIGS. 1 to 3, the pressure vessel, according to theinvention, illustratively is a pressure accumulator having a rigidcontainer of steel, aluminum or the like with two opposed fluid ports IIand I2. A deformable separator or partition l3 comprising, for, example,a bladder of elastic material, is positioned in the container I0 anddivides the interior space of the latter into two chambers 14 and 15having variable volumes. Chamber 14 communicates with port 11 whilechamber 15 communicates with port I2.

More particularly, chamber 14 is adapted to receive a fluid such as oiland port 11 is adapted to be connected to a hydraulic installation.Chamber I is filled by a gaseous fluid such as air or nitrogen underpressure and port I2 mounts a fitting 120, the bore of which receives agas inlet valve 13b in communication with chamber 15, the valve 13bbeing for example a conventional Schraeder valve which is normallyclosed. The mouth 13c of the bladder 13 is secured to the flange l2'a ofthe fitting 12a.

Means are provided to close the port II in response to expansion of thebladder 13 which tends to reduce or eliminate the volume of chamber 14.To this end the port 11 has a fixed seat 16 which is formed by theinside wall of the container around the port II and a movable closingelement or valve member 17 is provided, carried by bladder I3.

According to the invention, the valve member 17 is substantially cupshaped, the side wall 2I thereof having an inwardly extending annularflange 22. The floor of the valve member 17 has a concavity therein, inthe form of an inverted cone 19, the apex 19a of which is rounded asshown and illustratively extends beyond the plane of the annular flange22. The junction between the lower edge of side wall 21 and the base 20of the inverted cone 19 is rounded as at 18 and defines an annularclosure portion of diameter greater than that of port 11, so that suchclosure portion 18 may be moved against annular seat 16 to close port 11as shown in FIG. 3.

Illustratively, the diameter of the concavity l9 taken at the annularclosure portion 18 is between two and three times the height of theconcavity l9 and preferably approximately two and one-half times suchheight. The diameter of the annular closure portion 18 is between andI60 percent of the diameter of port II and preferably I40 percent ofsuch diameter.

As shown in FIG. 1, for example, the valve member 17 is preferablymolded integrally with the closed end I3a of the bladder 13 and isaxially aligned therewith, the apex 19 of the valve member 17 beingdirected upwardly as shown.

To charge the pressure accumulator hereinabove described. the port 11 isconnected to a hydraulic installation and gas under pressure is admittedthrough valve 13b into the chamber 15 defined by bladder 13 to chargethe latter which will expand, substantially to assume the contour of theinner wall of the container 10 and valve member 17 will seal as shown inFIG. 3 to close port 11.

A valve (not shown) interposed between the port II and the hydraulicinstallation is opened, so that oil under pressure will flow throughport 11 into chamber 14 and compress the gas in bladder 13, moving valvemember 17 off its seat 16 and opening port 1 l. The device is then inoperating condition.

In operation of the pressure accumulator, the oil contained in thechamber 14 will be forced through port ll into the hydraulicinstallation under the effect of the gas under pressure in bladder 13.As this occurs, the chamber 14 will empty and the annular closureportion 18 of valve member 17 will move onto the seat I6 in order toclose the port 11 to prevent extrusion of the bladder 13.

The concavity 19, according to the invention, provides for a properoperation as well as correct closing, and this, whether the outflow ofliquid from chamber 14 through port I I is large or small.

When the volume of this outflow is large, the concavity 19 has theeffect of creating a low pressure zone therebeneath, which produces asuction that provides a self-centering effect of the valve member 17with respect to the port 11, and the valve member 17 is applied andexactly centered by its rounded annular closure portion 18 upon the seatI6 in the closed position (FIG. 3).

When the volume of liquid outflow is small, and since the bladder [3 mayhave a more or less pronounced dis-symmetry due to its construction,there may occur a first contact of the closure portion I8 of valvemember 17 with the seat I6 in a localized region serving as a balancingpoint P (FIG. 2.).

In the space 8 existing between the valve member 17 and the seat 16opposite the balancing point P, there occurs a layering flow of the oiland by reason of the concavity 19 which causes a turbulence generating alow pressure area, there is a self-centering effect which brings thevalve member from the ajar balancing position of FIG. 2 to the positionof complete closing, properly centered, of FIG. 3.

The concavity 19, according to the invention, has in addition, theeffect, in case of a break in the line of the hydraulic installation towhich the port I l is connected, which will cause an extremely rapiddischarge to occur from chamber I4, and hence a large pressure drop, ofcausing an immediate seating of the valve member 17 upon the seat 16, ina proper self-centered position due to the suction created in theconcavity 19.

In the embodiment shown in FIG. 4, the arrangement is similar to thatpreviously described with reference to FIGS. I to 3, except for theconfiguration of the valve member 17'. Thus, the valve member 17' hassubstantially the shape of an inverted dish having a flat apex or topwall 24 and an outwardly flared side wall 23.

A flat disc 25 of diameter greater than that of top wall 24 is securedto the latter with the periphery 26 of the disc 25 extending laterallybeyond the periphery of the wall 24 so that the valve member may besecurely anchored in the closed end l3a of the bladder 13' when moldedintegrally therewith.

The rim 18' of the valve member 17' defines an annular closure portiondesigned to move against the seat 16' to close the port ll.

The concavity 19' of the valve member 17' has, in a plane passingthrough the axis thereof, a section in the form of a trapazoid, thelarger base 20' of which has a diameter between I20 and 220 percent ofthe small base or top wall 24 and preferably near l70 percent of suchdiameter. The diameter of the large base 20 of the trapazoid is between200 and 600 percent of the height of the concavity l9 and preferablynearly 400 percent of this height.

The operation of the valve member of FIG. 4 is similar to that which hasbeen described with reference to the embodiment of FIGS. 1 to 3.

in the embodiments shown in FIGS. 1 to 3 and in FIG. 4, the valve member17 or 17' is carried by the bladder l3, 13. in the embodiment shown inFIGS. to 7, the valve member 17" is separate from the bladder 13 and ismounted in the port ll" of the rigid container 10.

In the embodiment shown in FIGS. 5 to 7, the valve member 17" comprisesa hemispherical cap, the rim of which forms the annular closure portionis" that is movable against the seat 16', the interior of the capdefining the concavity 19".

A rod 27, secured at one end as at 27' to the interior of the capextends outwardly therefrom, being axially aligned with the openingdefined by the rim 18''.

The rod 27 extends through the central opening 31 of a wall 30 extendingtransversely across the inner end of port 11''. A coil spring 28encompassing rod 27 and reacting against the inner surface of cap l7"and wall 30, normally urges the cap 17" inwardly, such inward movementbeing limited by a stop member 29 secured to the end of rod 27 andabutting against the outer surface of wall 30. The diameter of stopmember 29 is such that when abutting against wall 30, it will not covera plurality of fluid passages 32 extending through such wall 30.

The stop member may be a disc that will completely cover central opening31 when the valve member 17" is in open position or it may have aconfiguration such as the shape of a cross, for example, to expose aportion of opening 3!.

The length of rod 27 is such that when the stop member abuts against theouter surface of wall 30 as shown in FIG. 5, the rim or annular closureportion 18" of the valve member 17" will be inwardly spaced from seat[6".

in the open position of valve member 17'', the spring 28 retains theannular closure portion 18" thereof spaced from the seat 16'', whichpermits flow of fluid through the annular space S provided between theclosure portion 18" and the seat 16 and through the passages 32 as wellas possibly through a part of the opening 3].

As the chamber 14" empties as a result of expansion of the bladder, theend l3 '0 of the bladder will press against the cap or valve member 17"moving the rim or closure portion 18" thereof against the seat 16" toclose port 11. The concavity l9" defined by the cap 17" functions as aself-centering device similar to the concavity 19 shown in FIGS. 1 to 3.When the outflow is great, the concavity 19" produces a low pressurearea having a self-centering effect assuring a properly centered closing(FIG. 7). When the outflow is small, the cap or valve member 17" isplaced in a balancing position (FIG. 6), leaving a space S" generating alayering flow of the fluid, which causes a turbulence and aself-centering suction effect, which will move the valve member 17" fromthe position shown in FIG. 6 to the correctly centered position ofcomplete closing of FIG. 7.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent of the United States is:

l. A pressure vessel comprising a container of rigid mate rial havingtwo ports, one of said ports being axially aligned with the containerand defining a liquid port, a deformable bladder of elastic materialsecured in said container separating said two ports from each other todefine two variable volume fluid receiving chambers, said bladderextending axially in said container and being closed at one end, theportion of the container adjacent the periphery of said liquid portdefining a valve seat, means movable against said valve seat to closesaid port, the closed end of said bladder being adapted to react againstsaid movable means to actuate the latter, said movable means comprisinga valve member having an annular closure portion adapted to be movedagainst said seat to close said liquid port, said closure member havinga concavity therein facing said liquid port, said concavity in crosssection being substantially conical, having its apex directed upwardlyand having a base diameter greater than the diameter of said liq uidport and between two and three times the height of said concavity, saidconcavity being subjected to the effect of liquid flow from said port tocreate a low pressure area in said concavity.

2. The combination set forth in claim I in which the diameter of thebase of the concavity is two and one-half times the height of theconcavity.

3. A pressure vessel comprising a container of rigid mate rial havingtwo ports, one of said ports being axially aligned with the containerand defining a liquid port, a deformable bladder of elastic materialsecured in said container separating said two ports from each other todefine two variable volume fluid receiving chambers, said bladderextending axially in said container and being closed at one end, theportion of the container adjacent the periphery of said liquid portdefining a valve seat, means movable against said valve seat to closesaid port, the closed end of said bladder being adapted to react againstsaid movable means to actuate the latter, said movable means comprisinga valve member having an annular closure portion adapted to be movedagainst said seat to close said liquid port, said closure member havinga. concavity therein facing said liquid port, said concavity being inthe form of an inverted dish having a substantially flat top wall and anoutwardly flared side wall, the diameter of the base of said concavitybeing between l20 and 220 percent of the diameter of the top wall andbetween 200 and 400 percent of the height of said concavity, saidclosure member having a base diameter greater than the diameter of saidliquid port, said concavity being subjected to the effect of liquid flowfrom said port to create a low pressure area in said concavity.

4. The combination set forth in claim 3 in which the diameter of thebase of said dish-shaped concavity is substantially of the diameter ofthe top wall and the diameter of the base of the concavity issubstantially 400% of the height of the concavity.

S. A pressure vessel comprising a container of rigid material having twoports, one of said ports being axially aligned with the container anddefining a liquid port, a deformable bladder of elastic material securedin said container separating said two ports from each other to definetwo variable volume fluid receiving chambers, said bladder extendingaxially in said container and being closed at one end, the portion ofthe container adjacent the periphery of said liquid port defining avalve seat, means movable against said valve seat to close said port,the closed end of said bladder being adapted to react against saidmovable means to actuate the latter, said movable means comprising avalve member having an annular closure portion adapted to be movedagainst said seat to close said liquid port, said valve member beingsubstantially in the form of an inverted dish having a flat top wall andan outwardly flared side wall defining a concavity having a mouth ofdiameter greater than the diameter of said liquid port, a disc securedto said top wall and of diameter greater than the diameter of said topwall, said valve member being molded integrally with the closed end ofsaid bladder and axially aligned therewith, the base of said dish-shapedmember defining the annular closure, said concavity being subjected tothe effect of liquid flow from said port to create a low pressure areain said concavity.

I l 1. 1K

1. A pressure vessel comprising a container of rigid material having twoports, one of said ports being axially aligned with the container anddefining a liquid port, a deformable bladder of elastic material securedin said container separating said two ports from each other to definetwo variable volume fluid receiving chambers, said bladder extendingaxially in said container and being closed at one end, the portion ofthe container adjacent the periphery of said liquid port defining avalve seat, means movable against said valve seat to close said port,the closed end of said bladder being adapted to react against saidmovable means to actuate the latter, said movable means comprising avalve member having an annular closure portion adapted to be movedagainst said seat to close said liquid port, said closure member havinga concavity therein facing said liquid port, said concavity in crosssection being substantially conical, having its apex directed upwardlyand having a base diameter greater than the diameter of said liquid portand between two and three times the height of said concavity, saidconcavity being subjected to the effect of liquid flow from said port tocreate a low pressure area in said concavity.
 2. The combination setforth in claim 1 in which the diameter of the base of the concavity istwo and one-half times the height of the concavity.
 3. A pressure vesselcomprising a container of rigid material having two ports, one of saidports being axially aligned with the container and defining a liquidport, a deformable bladder of elastic material secured in said containerseparating said two ports from each other to define two variable volumefluid receiving chambers, said bladder extending axially in saidcontainer aNd being closed at one end, the portion of the containeradjacent the periphery of said liquid port defining a valve seat, meansmovable against said valve seat to close said port, the closed end ofsaid bladder being adapted to react against said movable means toactuate the latter, said movable means comprising a valve member havingan annular closure portion adapted to be moved against said seat toclose said liquid port, said closure member having a concavity thereinfacing said liquid port, said concavity being in the form of an inverteddish having a substantially flat top wall and an outwardly flared sidewall, the diameter of the base of said concavity being between 120 and220 percent of the diameter of the top wall and between 200 and 400percent of the height of said concavity, said closure member having abase diameter greater than the diameter of said liquid port, saidconcavity being subjected to the effect of liquid flow from said port tocreate a low pressure area in said concavity.
 4. The combination setforth in claim 3 in which the diameter of the base of said dish-shapedconcavity is substantially 170% of the diameter of the top wall and thediameter of the base of the concavity is substantially 400% of theheight of the concavity.
 5. A pressure vessel comprising a container ofrigid material having two ports, one of said ports being axially alignedwith the container and defining a liquid port, a deformable bladder ofelastic material secured in said container separating said two portsfrom each other to define two variable volume fluid receiving chambers,said bladder extending axially in said container and being closed at oneend, the portion of the container adjacent the periphery of said liquidport defining a valve seat, means movable against said valve seat toclose said port, the closed end of said bladder being adapted to reactagainst said movable means to actuate the latter, said movable meanscomprising a valve member having an annular closure portion adapted tobe moved against said seat to close said liquid port, said valve memberbeing substantially in the form of an inverted dish having a flat topwall and an outwardly flared side wall defining a concavity having amouth of diameter greater than the diameter of said liquid port, a discsecured to said top wall and of diameter greater than the diameter ofsaid top wall, said valve member being molded integrally with the closedend of said bladder and axially aligned therewith, the base of saiddish-shaped member defining the annular closure, said concavity beingsubjected to the effect of liquid flow from said port to create a lowpressure area in said concavity.